Indicating mechanism



C. l. McNElL INDICATING MECHANISM Nov. 1, 193s.

Filed sept. 2a, l1935 IN VEN TOR.

UNi'rED STATES PATENT oFElcE INDICATING MECHANISM `clarion I. MoNou, Bloomnoia, N. J., signor to Eclipse Aviation Corporation, East Orange, N. J., a corporation of New Jersey Application september 2s, 1933, serial No. 691,409

is shown in a form suitable for indicating the pressure of a liquid in a closed container, or iiowing through a closed conduit; but it is to be understood that the drawings are merely for the purpose of illustration and description and Ado not constitute a .denition `of` the limits of the invention, reference being had to the appended claims for such a denition o! limits.

In the drawings,

Fig. 1 is a schematic representation of the parts employed-in the preferred embodiment of the invention, and the electrical energizing means for said parts;

Fig. 2 is a longitudinal sectional view of th .impulse sending. or measuring unit;

Fig. 3 is a longitudinal section'aLview of thel impulse receiving, or indicating unit; and,

Fig. 4 is a transverse sectional view along the line 4-4 of Fig. 3.

The primary impulse sending mechanism is shown in Fig. 2 as including a pair of normally separated current conducting switch elements 5 and 6, the former being stationary and the latter being resilient and movable to alternately make and break a circuit by alternate contact with and separation from the contact 5. The means for effecting the alternate engagement and disengagement of the contacts 5 and 6 in response to changes in pressure in the container or conduit, whose pressure is to be indicated, preferably includes a reciprocable element subjected to the pressure ofthe uid in the container orv conduit, and also subjected to op-v positely directed mechanical and electro-magnetic forces.

As shown in Fig. 2 theviiuid receiving portion of the switch actuating element is.. in the form of a exible bellows 1 constructed of suitably corrugated metal fastened to the case 8 at one end by suitable means 9, and adapted to expand in a direction away from said stationary end as the fluidentering the bellows through the connection II exerts pressure upon said bellows, causing-the lower end I2 thereof to exert a downward pressure upon the magnetizable core or plunger I3 of an electro-magnetic device I4 having a winding I6 adapted to be energized at regular intervals by means to be de`- scribed. This tendency to produce a downward movementof the core I3 is opposed by suitable means such as compression springs I8 and I9 mounted on abutments 2| and 22 respectively, the upper end of the spring I9 being engageable with the core I3 as shown, and the upper end follower.

of the spring I8 being engageable with a disc 2 4 interposed between the upper end of the core I3 and the lower end wall of the bellows.

In order to translate the reciprocatory inovement of the plunger I3 into vibrating motionon the -part of the contact 6, the former is provided with a series of circumferential grooves or corrugations shown at V2'I, with respect to which corrugations the correspondingly tapered shank28 of the switch element 6 acts as a cam 'Ihe' size and setting or the spring I9, in relation to the electro-magnetic strength of the coil I6, is preferably such that'the said spring effectually prevents movement of the plunger I3 to a position lower than that indicated in Fig. 24 prior to the energizationv of the said vwinding I6, butis yieldable to permit such downward movement in response tothe passage of current through the winding le. Following de-energization of winding I6 thev extent of the return movement (and therefore the number of vibrations of the contact 6) is directly proportionate to the pressure being exerted upon the bellows 1 by the fluid in the container or conshown in Figs. 3 and 4 as involving a pair of electro-magnetic devices 36 and 31, the latter having acore 38 adapted, when current is passed through the winding of the solenoid,vto'attract an armature 39 pivoted to the casing 4I, as indicated-at 42, and having a vlatch or pawl 43 pivotally connected to its opposite end, as indicated at 44, said latch or pawl being adapted to cooperate with the teeth of a ratchet disc 46 securedto a shaft 41 rotatably mounted in the side walls 48 and 49 respectively, of the,casing 4|, and having securedthereto at its outer end a pointer 5I movable across vthe face of a dial 52 bearing', suitable flgures to indicate the pressure existing in the conduit Il.v A spring 56 is wound'spirally, with one end passing through the sha'aft'41 as indicated'at 51 in Fig. 3, and the opposite'end held iixed by suitable means 58 secured to the vcasing as indicated in Fig. 4, the direction ofthe winding ofthe spring 56 being such as to cause rotation of the shaft 41 to a position which brings the pointer 5I 'to the zero, or non-indicating position on the scale 52 (Fig. l) upon release of the pawl 43 by the means now to be described. In the arrangement shown, the dial scale is such that clock- `wise movement of the pointer produces pro- 43 in the respective positions indicated in Fig. 3,

with pawl 43 in engagement with one of the teeth of the ratchet disc 46. 'I'hese springs also act to insure contact of the pawl 43 with successive teeth of the ratchet disc, and thereby impart a step by step rotation to said disc (and-hence to the pointer 5| in response to repeated energizations of the electro-magnetic device 31 in the manner to bedescribed, such step by step action continuing until such energizations are interrupted. Meanwhile a resilient detent 48 maintains the disc in the position to which it has been .'rotateduntil a disengaging force is exerted thereupon. In the embodiment shown, such disengaging force is exerted by the magnetic attraction of core 68 upon an armature 18 having a depend- 'ing lug 15 extending under and engaging the pawl 43 to raise the latter in response to energization of the winding 36.

As indicated in Fig'. 1, the winding 36 is electrically connected in series relation with the winding I 6 of the solenoid I4 :and is therefore energized concurrently with said winding I6, such concurbattery 14, the negative terminal .of which is grounded as indicated at 16, and the return lead 11 from the coil 36 being similarly grounded as indicated at 18. The means for closing the contacts 1I and 12 at regular intervals may be of any suitable construction, and is indicated in Fig. 1 as including a constant speed'timing motor T. M. adapted to be venergized from any suitable source, such as the battery 14, and adapted to drive a low speed shaikl through a suitable gear train (not shownlcausing the said shaft to rotate at a speed, lfor example, of revolutions per minute, so that 'the cam carrying disc 82 of said shaft will act to close a circuit through the contacts 1I and 12 at intervals of 3 seconds or thereabouts. The electro-magnet 31 is also preferably energizable from the 'same source 14 which energizes the electro-magnets I4 and 36, and the circuit thereto includes the above described conductor 13, also a lead 86 connecting with the above described switch contact 5, and a second lead 81 connecting the movable contact 6 with the terminal post 88 to which the winding of the electro-magnet 31 is connected as indicated at 89 in Fig. 3, the other end of said winding being grounded as indicated at 9| in Figs. 1 and 3.

g In` the beginning of the cycle of operation, the rotor T. M. is assumed to be energized (the switch -93 having been previously closed) and the rst return the pointer 5I to the non-indicating position on thedial. At the same time the energization of thevwindingV I6 of the solenoid I4 attracts the plunger I3 toward the abutment 22. 'I'his energization is but momentary, however, since the cam on the disc 82 occupies but a small portion of the periphery thereof; and the resulting deenergization of the winding I6 allows spring I8 to return the plunger I3 toward the position indicated in Fig. 2, the degree of return depending upon the pressure existingvin the bellows 'I as 43, thus causing the disc 46 to be rotated step by' step and a corresponding indication to be registered by the pointer 5I upon the dial 52, the pointer moving in a clockwise direction, as viewed in Fig. 1. 'I'he pressure in the conduit I I forthe instant is thus indicated, subject to alteration upon the next closure of the contacts 1I and 12 if the pressure in the conduit II undergoes even a very slight change in the intervening interval, it being understood that the pointer returns to the non-indicating position by the action of the coil spring 56 prior to assuming its new position.

It is to be seen from the foregoing that the invention provides means for producing continual, although not continuous, indications of the slightest changes in the pressure or other physical property of the fluid to be measured, and makes it possible to produce such an indication on a dial disposed in a location remote from the fluid containing conduit, the only connection therebetween being of an electrical nature and thus eliminating the necessity of extending tubes or mechanical transmitting means from one unit to the other.

If it is desired to have the pressure at any thus preserving -a record of the pressure then existing.

If it is desired to indicate temperature, for example, rather than pressure, this may be done by lling the expansible chamber 1 with a volatile fluid, and substituting a bulb at the point of connection indicated at II in Fig. 2. Itis also un.

derstood that changes may be'made in the con-5 struction, arrangement and number of the parts employed, as well as in their interrelation and method of operation, within the. scope of the appended claims.

What is claimed is:

1. The combination of a transmitting means having a solenoid mounted at one end thereof, an armature extending from said solenoid, a movable element at the opposite endof said casing for limiting the movement of said armature, said element movable in response to some external condition to be measured; resilient means for constantly urging said armature toward said movable element, a pair of electrical contacts, means associated with the armature for opening and closing said contacts a number of times proportional to the extent of movement of said armature, whereby an index element of an elec'- trically controlled receiving means is moved proportionally lto the movement of said armature,

` said index elementhaving an initial position,

means constantly tending to return said index element to its initial position, electromagnetically controlled ratchet and pawlmeans for moving said index element step by step from said initial position to spaced apart new positions in response to the opening' and closing of an electrical circuitincluding said electromagnet by said conagainst return movement as it proceeds step by step from one position to another, a second electromagnetic means for rendering said holding means ineffective, contact means operable at intervals for simultaneously energizing a circuit including said solenoid and a circuit including said-second electromagnetic means whereby said holding means is rendered ineffective to allow an uninterrupted, single step return movement of said index element to said initial position.

2. The combinaton of a, transmitting means having a solenoid, an armature extending vfrom said solenoid, a movable element for limiting the movement of said armature, said elementbeing movable in response to some external condition to be measured, resilient ,means for constantly urging said 'armature toward said movable element, a pair of electrical contacts, means asso-- ciated with the armature for opening and closing said contacts a number of times proportional to the extent of movement of said armature, whereby an index element of an electrically controlled receiving means is moved proportionally to the movement of said armature, said index element having an initial position, means constantly tending to return said index element to its initial position, electromagnetically controlled ratchet and pawl means for moving said index element step by step from said initial position to spaced apart new positions in response to the opening and closing oi' an electrical circuit including said electromagnet by said contacts, pawl means for holding said element against return movement as it proceeds step by step from one position to another, a-second electromagnetic means for rendering said holding means ineffective, contact means operable at intervals for simultaneously energizing a circuit including said solenoid and a circuit includingnsaid second electromagnetic means whereby said holding means is rendered ineffective to allow an uninterrupted, single step return movement of said index element to said initial position.

3. The combination of a transmitting means having a solenoid, an armature extending from `said solenoid, akmovable element for Hunting the movement of said armature, said element being movable in response to some external condition to be measured, resilient means for constantly `urging said armature toward said movable element, a pair of electrical contacts, means associated with the armature for opening and closing said contacts a number of times proportional to the extent of movement of said armature, whereby an index element of an electrically controlled receiving means is moved proportionally to the v, movem'ent of said armature, said index element fhaving an initial position, means constantly tending to return said index element to its initial position, electromagnetically controlled means 'for moving said index element step by step from f ond electromagneticmeans for rendering saidholding means ineiIective, contact means operable at intervals for simultaneously energizing a circuit including said solenoid and a circuit including said second electromagnetic meanswhereby said holding means is rendered ineffective to allow an uninterrupted, single step return movement of said index element to said initial position.

4. The combination of a transmitting means having a solenoid, an armature extending from said solenoid, a movable element for limiting the movement of said armature, said element being movable in response to some external condition to be measured, resilient means :for constantly urging said armature toward said movable element, a pair of electrical contacts, means associated with the armature for opening and closing said contacts a number of times proportional to the extent of movement of said armature, whereby an index element of an electrically controlled receiving means is moved proportionally to the movement of said armature, said index element -having an initial position, means constantly intervals for simultaneously energizing a circuit including said solenoid 'and a circuit including said second electromagnetic means whereby said holding means is rendered ineffective to allow an uninterrupted, lsingle step return movement of l said index element to said initial position.

5. Thecombination-of a transmitting means i having a solenoid, an armature extending from said solenoid, a movable element for limiting the movement of said armature, said element being movable in response to some external condition to be measured, resilient means for urging said armature toward said movable element, an electric circuit breaker, means associated with the armature for opening and closing said circuit breaker a number of times proportional to the Aextent of movement of said armature, whereby trical circuit including said electromagnet by said contacts, means -ior holding said element against'return movement as it proceeds step by step from one position to another, a secondl electromagnetic means for rendering said holding means ineffective, contact means operable at intervals forsimultaneously energizing a circuit including said solenoid and a circuit including.

said second electromagnetic means whereby said holding means is rendered ineffective to allow an uninterrupted, single step return movement of said index element to said initial position.

CHARLES I. McNEIL. 

